Light emitting diode with pads on side surface thereof, light emitting device and display device including the light emitting diode

Abstract

The present application relates to a light emitting diode, a light emitting device, and a display device. The light emitting device includes a light emitting diode and a substrate; the substrate is coated with a bonding substance; the light emitting diode is provided with a positive electrode pad and a negative electrode pad; the surface of the positive electrode pad and/or the negative electrode pad is provided with a plurality of protrusions which are embedded in the bonding substance; and the positive electrode pads and the negative electrode pads are fixed to the substrate through the bonding substance. The embodiment of the present application provides projections on the pad of the light emitting diode, avoids the need of increasing the area of the pad, increases the contact area between the pad and the solder with the constant pad area, improves the bonding stability between the light emitting diode and the substrate, and reduces the production cost.

Claims

1. A light emitting device comprising: a light emitting diode and a substrate; wherein the substrate comprises a groove, the light emitting diode is in the groove, wherein the light emitting device further comprises a bonding substance between the light emitting diode and the substrate, the bonding substances fills a space between the light emitting diode and the substrate and fixes the light emitting diode in the groove, wherein the light emitting diode comprises a positive electrode pad and a negative electrode pad, each of the positive electrode pad and the negative electrode pad comprises a plurality of protrusions, the plurality of protrusions are embedded in the bonding substance, wherein the positive electrode pad and the negative electrode pad are fixed to the substrate through the bonding substance, wherein the positive electrode pad and the negative electrode pad are only located on two side surfaces of the light emitting diode and in direct contact with the light emitting diode, and the two side surfaces of the light emitting diode are opposite to each other and perpendicular to a bottom surface of the light emitting diode, wherein an area of the positive electrode pad is smaller than that of the negative electrode pad.

2. A light emitting device according to claim 1, wherein the protrusions have a cross-section of rectangular, triangular, or wavy shape.

3. A light emitting device according to claim 1, wherein the bonding substance is solder.

4. A light emitting device according to claim 1, wherein each of the protrusions extends in a direction perpendicular to the plane at which the positive electrode pad and the negative electrode pad are located.

5. A light emitting device according to claim 1, wherein the protrusions are formed on the surface of the positive electrode pad and the negative electrode pad using die casting, 3D printing, wiredrawing or spraying.

6. A light emitting device according to claim 1, wherein the light emitting diode and the substrate coated with the bonding substance are fixedly connected by means of thermal baking after aligning.

7. A display device comprising the light emitting device according to claim 1.

Description

BRIEF DESCRIPTION OF FIGURES

(1) The features and advantages of the present application will become more apparent from the following description with reference to the accompanying drawings, which are schematic and not to be construed as limiting the scope of the present application, in which drawings:

(2) FIG. 1 shows a schematic view of the structure of a light emitting device according to an embodiment of the present application;

(3) FIGS. 2a, 2b, and 2c show a schematic cross-sectional view of the protrusions of the present application;

(4) FIG. 3 shows a schematic view of the structure of a light emitting device according to another embodiment of the present application;

(5) FIGS. 4a, 4b, and 4c show a schematic structural view of a light emitting device according to still another embodiment of the present application.

DETAILED IMPLEMENTATIONS

(6) Hereinafter, embodiments of the present application will be described in detail with reference to the accompanying drawings.

(7) FIG. 1 shows a schematic structural view of a light emitting device according to an embodiment of the present application. As shown in FIG. 1, the light emitting device of this embodiment includes a light emitting diode 1 and a substrate 2, wherein the substrate 2 is coated with a bonding substance 3. The light emitting diode 1 is provided with a positive electrode pad 11 and a negative electrode pad 12, and the surfaces of the positive electrode pad 11 and the negative electrode pad 12 are provided with a plurality of protrusions embedded in the bonding substance 3, and the positive electrode pad 11 and the negative electrode pad 12 are fixed to the substrate 2 by bonding substance 3.

(8) In a practical application, the contact area between the pad and the solder can be increased by providing the protrusions only on the surface of the positive electrode pad 11 or only on the surface of the negative electrode pad 12. In order to further increase the contact area between the pad and the solder, the surfaces of both the positive electrode pad 11 and the negative electrode pad 12 are usually provided with protrusions to enhance the bonding stability of the light-emitting diode and the substrate.

(9) The light-emitting device of the present embodiment increases the contact area between the pad and the solder by providing the protrusions on the pad of the light-emitting diode with a constant pad area, and improves the bonding stability of the light-emitting diode and the substrate, does not need relying on a lager area of the pad for improving the bonding stability of the light-emitting diode and the substrate, which reduces the manufacturing cost. At the same time, the projections provided on the pad on the light-emitting diode are more conducive to heat dissipation, extending the life of the light-emitting diodes.

(10) The positive electrode pad 11 and the negative electrode pad 12 shown in FIG. 1 are located on the bottom surface of the light emitting diode 1. The area of the positive electrode pad 11 is smaller than the area of the negative electrode pad 12. It is to be noted that, in practical applications, the positive electrode pad 11 and/or the negative electrode pad 12 may be provided on the side surfaces of the light emitting diode as required.

(11) FIG. 2 is a schematic cross-sectional view of the protrusion. As shown in FIG. 2, the cross-section of the protrusion on the surface of the positive electrode pad has a rectangular (FIG. 2a), triangular (FIG. 2b) or wavy (FIG. 2c) shape. Of course it will be understood that the invention is not limited thereto and that the cross-sectional shape may also be other irregular shapes. The protrusions are preferably microbumps having dimensions in the range of a few microns to several tens of microns in directions of width and height. The width direction is a direction parallel to the surface of the pad, and the height direction is a direction perpendicular to the surface of the pad.

(12) Preferably, the bonding substance 3 is solder, which may be tin-lead alloy solder, antimony-contained solder, cadmium-contained solder, silver-contained solder or copper-contained solder. Employing the solder as a bonding substance of the light-emitting diode and the substrate can enhance the bonding stability of the light-emitting diodes and substrates.

(13) In order to further increase the contact area between the pad and the solder, the extension direction of the protrusion is set perpendicular to the plane where the pad is located, to further enhance the bonding stability of the light-emitting diode and the substrate, thereby avoiding the increase in the production cost due to the increase of the pad area.

(14) In practical applications, the protrusions are formed on the surface of the pads by die casting, 3D printing, wire drawing or spraying; the light-emitting diodes and the substrate coated with the bonding substance are fixedly connected by means of thermal baking after aligning. It is not limited by this embodiment.

(15) FIG. 3 shows a schematic structural view of a light emitting device according to another embodiment of the present application. The embodiment shown in FIG. 3 is substantially the same as the embodiment shown in FIG. 1, with the main difference being that the substrate 2 is provided with a groove in which the light emitting diode 1 is located. Optionally, a portion of the light emitting diode 1 is located in the groove and the other portion thereof protrudes out of the groove.

(16) FIG. 4a shows a schematic structural view of a light emitting device according to still another embodiment of the present application. The embodiment shown in FIG. 4a is substantially the same as the embodiment shown in FIG. 1, with the main difference being that the positive electrode pad 11 and the negative electrode pad 12 of the embodiment shown in FIG. 4a are located on the bottom surface and side surfaces of the light emitting diode 1; and the substrate 2 is provided with a groove in which the light emitting diode 1 is located. Optionally, the light emitting diode is fully embedded in the groove.

(17) As a variation of this embodiment, the positive electrode pad 11 and the negative electrode pad 12 may be provided only on the side surfaces of the light emitting diode (as shown in FIG. 4b).

(18) As another variation of this embodiment, the positive electrode pad 11 may be provided on the side surface of the light emitting diode, and the negative electrode pad 12 is provided on the bottom surface of the light emitting diode (as shown in FIG. 4c).

(19) The present application also provides a display device comprising the above-described light emitting device. The display device provided in the present embodiment may be any product having display function, such as a notebook computer display screen, an outdoor large screen, a television, a digital camera, a mobile phone, a tablet computer, or the like. Therein, the light-emitting diode can be used as an indicator of the display device, and can also be used as a backlight of the display device. By setting the protruding structure on the pad of the light-emitting diode, the contact area between the pad and the solder is increased, and the bonding stability of the light-emitting diode and the substrate is improved. At the same time, the projection on the pad on the light-emitting diode is more conducive to heat dissipation, extending the life of the light-emitting diodes. The backlight of the display device requires a plurality of light emitting diodes. Thus reducing the manufacturing cost of a single light emitting diode can reduce the overall manufacturing cost of the display device.

(20) The light-emitting device and the display device provided by the present application provide a protruding structure on the pad of the light-emitting diode, increase the contact area between the pad and the solder, enhance the bonding stability of the light-emitting diode and the substrate, and reduce the manufacturing cost. At the same time, the projection on the pad on the light-emitting diode is more conducive to heat dissipation, extending the life of the light-emitting diodes.

(21) While the embodiments of the present application have been described in connection with the accompanying drawings, those skilled in the art will be able to make various modifications and variations without departing from the spirit and scope of the present application. Such modifications and variations are all within the scope defined by the claims. In the description of the present application, it is to be understood that the azimuth or positional relationship indicated by the terms up, down, inside, outside, etc. is based on the azimuth or positional relationship shown in the drawings, only for facilitating the description of the present application and simplifying the description, rather than indicating or implying that the device or element is intended to have a particular orientation, is constructed and operated in a particular orientation and is therefore not to be construed as limiting the present application. The phrase comprising does not exclude the presence of elements or steps not listed in the claims. The wording a or an preceding the element does not exclude the presence of a plurality of such elements. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that the combination of these measures can not be used for advantage. Any reference signs in the claims should not be construed as limiting the scope.